hey all, my issue: 2.5l wrangler, fires up fine with a high idle, over 2000, immediately drops to around 800-1000 rpm, when i go to drive it, she starts bucking like its running out of gas and trying to stall. things ive checked: tps, map, crank sensors, fuel pressure, fuel filter, pickup screen, fuel pump 1 yr old but pressure is good, manifold temp sensor, cap n rotor, plugs, replaced to ignition control module as it tested bad at both autozone and discount. when i installed the new icm it ran great at an idle for about 5 mins then started acting up. if i let it stall and do not reset the key switch it will fire up fine for a few more minutes then start acting up again. starting to loose my patience and considering selling it to just be done with it, but i love my jeep. any thoughts? from what ive read there is no diagnostic on this thing and ive checked the sensors using voltage and ohm tests ive found on all the forums. thanks a bunch.
noticed today while working on the jeep, i plugged the vac line going to the egr valve and tapped on the valve to see if it was stuck open, no change whatsoever, so i focused my attention to the map sensor again, while the jeep is running rough if i unplugg the vac line into the map sensor and put my thumb over the hole, on the line not the sensor, it smooths out but as soon as i plug the line back on it starts stalling out again, could i have a bad map sensor?
ok unplugged the o2 sensor, jeep fired up and ran like crap, ie very rough, put it in gear and tried to drive it but as soon as I stepped on the pedal to give it gas it started bogging out like it normally does. as far as it just running rougher it acted exactly the same. let me clarify, it does not stall just sitting at an idle for almost 10 mins, but as soon as I try to drive it, even if its the first attempt for the day, it will start to stall. I unplugged the map sensor vac line and plugged it, after I reset the comp from the o2 test, and tried to drive it, of course it died, but it ran for over 10 mins without a problem at idle. if I unplug the wiring plug from the map sensor it just shuts off. thoughts?
I read that only the multiport injection retains pressure which is why it has the bleed valve and that this system only has pressure when running. Thoughts? The fuel pump is about a year old but, I know that means squat, but having good pressure while its trying to stall? Should I recheck all the sensors since I replaced a faulty ignition control module?
Ok at the request of a friend I changed th vacuum line to the map, said it was squishy, no difference, so one by one I started unplugging things one at a time to check for changes. It seems that as the engine starts to come to temp is when its starts acting up. Upon inital start up the idle is around 3000 rpm then it immediately drops to around 2000, after about 2-3 mins idle then drops to around 1000 rpm and that is when trouble starts. I unplugged the manifold sensor on top of the intake, the one under the throttlebody in the intake and the o2, and although it runs differently it always acts up the same.